Soft corals are found in oceans and seas throughout the world, mostly at depths between five and thirty meters. Instead of calcium carbonate skeletons, these animals contain tiny skeletal elements called sclerites, which give them shape and support. In addition, these sclerites deter some predators from feeding on them. In the past, soft corals were believed to be unable to build reefs, but current knowledge has proven that they are capable of cementing sclerites at their bases, adding slowly to reefs over time.
Unlike hard or stony corals, soft corals can thrive in water where little light penetrates, and many species are capable of extending to feed from nutrients in water we might think of as a bit too murky for diving. Most soft coral species feed on whatever happens to float past, including zooplankton and particles of detritus. Providing important habitats for fish and algae, snails, sea horses, and other marine life, they are an integral part of the reef ecosystem. Like other reef life, soft corals are vulnerable. The aquarium trade threatens soft coral species by taking cuttings for hobbyists, even though soft corals can be grown via aquaculture instead of harvested from wild sources.
Soft Coral Species
There are thousands of species of soft coral, and no matter where you dive, you’re likely to encounter at least a few, so long as the environment is conducive to the health of marine life. Whether you dive wrecks, walls, or reefs, you may come across some of these common species:
Carnation Coral
Mostly found in the Indo-Pacific, Carnation corals are at risk due to changes in water chemistry. Some of the most beautiful examples can be found beneath overhangs and growing inside caves. You’ll find Carnation coral in places like Fiji, the Solomon Islands, and Australia’s Great Barrier Reef.
Xenia Corals
Found in the Indo-Pacific and the Red Sea, Xenia Corals are often quite lush, with a tendency to pulse. This type of soft coral prefers bright light and is not normally found at depths beyond about 10 meters. It is often white or light brown with contrasting polyps. These filter feeders are often found in areas where the water is slightly polluted, for example they are commonly encountered near pipes that carry grey water away from resorts.
Toadstool Corals
Some examples of toadstool corals include leather and mushroom leather coral, and trought coral. Usually found in shades of light tan to brown, with gold or white polyps, these corals can grow to be as large as three feet in diameter, and are found throughout the South Pacific.
Tree Corals
Found in many places throughout the world, these corals come in many different colors. You’ll normally encounter tree corals in reefs, attached to jetties, and on shipwrecks. These corals have a thick stem that attaches to hard surfaces on one end, and which terminates in several small branches.
Sea Whips, Sea Pens, and Gorgonians
A huge variety of species can be found worldwide in various shapes and sizes. As a group, these are often referred to as Octocorals. Rarely found at depths above 10 meters, many of these species prefer to live in dark, well protected areas. They come in brilliant shades ranging from yellow to orange to purple and red, and gorgonians in particular tend to provide habitats for small creatures. Often, colonies of pygmy seahorses rely on gorgonians for protection.
While these are just a few of the most commonly encountered types of soft corals, what you’ll find depends mainly upon where you dive. Remember, never touch soft coral – their structures are delicate and easily damaged. Practicing good conservation now will help ensure that these beautiful animals thrive in the future.